The observation of the charmoniumlike states such as the \(X(3872)\)  [1]},
the \(Y(4260)\)  [2]}, and the \(Z_c(3900)\)  [3]} indicates
that the hadrons are more complicated
than the expectations in quark models. The exotic properties of these
states such as very close to open charm thresholds and large coupling to
hidden-charm final states may suggest they are hadronic states beyond
the conventional quark model [4]}.
Search for their decays into light hadrons
will also shed light on their nature. Considering the small coupling
to open charm final states, we may even expect a state like the \(\psi (4230)\)  [5]}
(the dominant component of the \(Y(4260)\)  structure) has a larger
decay rate to the charmless final state than a charmonium state does.
These discussions can be extended to other vector charmoniumlike
states such as the \(Y(4360)\)  and \(Y(4660)\)  [6]}.
